<html>
	<head>
		<title>瀑布流</title>
		<style type="text/css">
			.div1, .div2, .div3 {
				float: left;
				margin: 0 10px;
				width: 30%;
			}
			.div1 div , .div2 div, .div3 div{
				width: 100%;
			}
		</style>
	</head>
	<body>
		<div class="div1">
			<div style="height: 100px;background-color: red"></div>
			<div style="height: 200px;background-color: gray"></div>
			<div style="height: 300px;background-color: green"></div>
		</div>
		<div class="div2">
			<div style="height: 200px;background-color: red"></div>
			<div style="height: 200px;background-color: gray"></div>
			<div style="height: 200px;background-color: green"></div>
		</div>
		<div class="div3">
			<div style="height: 300px;background-color: red"></div>
			<div style="height: 200px;background-color: gray"></div>
			<div style="height: 100px;background-color: green"></div>
		</div>
	</body>
</html>